To localize possible abnormal patterns of cerebral glucose metabolism and cerebral blood flow in adults with Attention Deficit Disorder (ADD) Residual Type, parents of diagnosed hyperactive children are being studied using the 2- deoxyfluoroglucose method of Positron Emission Tomography (PET). To date, 30 PET scans have been performed without medication and 16 scans have been done during treatment with dextroamphetamine. To understand the mechanism of action of stimulant medication in the treatment of Attention Deficit Disorder with Hyperactivity (ADDH), a comparison of pemoline (Cylert), methylphenidate, and dextroamphetamine was initiated to examine the acute and chronic effects of these medications in the same subjects on peripheral measures of dopamine, norepinephrine, prolactin, and growth hormone. The relationships between the behavioral dimensions of impulsivity, aggression, and concentrations of monoamine metabolites, particularly 5-HIAA, in the spinal fluid of children with conduct disorder and/or attention deficit disorder, is being examined. Associations between decreased CSF 5-HIAA concentrations and impulsive aggressive behavior have been reported in impulsive adults. Peripheral measures of serotonin and catecholamines are being obtained along with personality, impulsivity and aggression measures. Seventeen subjects have been studied to date. A preliminary comparison between ten Conduct Disorder and ten age-matched Obsessive Compulsive children, shows a trend (p =.09) for lower CSF 5-HIAA concentration in conduct disorder. Within the conduct disorder sample, lower values are associated with more destructive behavior.